Microorganism-mediated synergistic degradation of antibiotics in wastewater via dual-electric centers.

Dissolved organic carbon (DOC) plays a trade-off effect in the transformation of antibiotics. However, how to actively utilize DOC to facilitate antibiotic elimination in biofilter remains a challenge. We employed a dual-electric centers catalyst consisting of graphene-like carbon nitride complex Cu-doped Al2O3 on commercial alumina (GL-Cu-Al2O3/Alumina) in biofilter to treat multiple antibiotics in municipal wastewater without external energy. The biofilter achieved removal efficiencies of 74.6% for ciprofloxacin (CIP) and 96.4% for sulfadiazine (SDZ) alongside a 46.6% reduction in antibiotic resistance genes. The synergistic coordination between the polar DOC-CIP-SDZ complex and extracellular polymeric substance (EPS) at the dual-electric centers drove the continuous interfacial electron transfer from the polar complex → GL → Cu sites → EPS → microorganisms, triggering the preferential cleavage of SDZ, followed by CIP. Moreover, the electron transfer from Cu sites to microorganism promoted the expression of genes associated with the synthesis of extracellular proteins, riboflavin, and e-pili. Concurrently, it facilitated exogenous electron-facilitated electrotrophic energy metabolism, such as fumarate reduction and CO2 fixation, optimizing microbial energy structure. Our findings presented a viable green strategy for sustainable management of water environments.